This invention relates generally to beverage dispensing and brewing systems, and in particular with a system for monitoring and controlling a beverage brewer.
Many different coffee brewing systems have been designed. Most utilize a pump, such as a peristaltic pump, to transfer water from a reservoir through a conduit to a brewing chamber. The pump is turned on at the beginning of a brewing cycle and at the end of a specific time period the pump is turned off. Other brewing systems use an electrically controlled device to open a valve at the bottom of a reservoir. Through gravity the water travels through a conduit to a brewing chamber. Again at the end of a specific time period, the valve is closed. These prior brewing systems lack the capability of consistently dispensing equal volumes of liquid. The systems are dependent on the accuracy of the timers, the pressure of the liquid, etc.
Therefore, there is a need for an automated beverage brewing system for dispensing a predetermined volume of liquid from a storage tank.
Briefly, according to an aspect of the present invention, a beverage brewing system uses compressed air to drive liquid from a metering chamber for use in preparing a brewed beverage.
An automated beverage brewing system receives a cartridge containing a beverage extract and establishes a liquid flow path through the cartridge to provide a brewed beverage. The system includes a holder that holds and pierces the cartridge to provide a cartridge inlet and a cartridge outlet that together establish a flow path through the beverage extract to provide the brewed beverage. A storage tank comprising a supply of liquid and having a reduced diameter cup-shaped bottom is in fluid communication with the cartridge via a chamber outlet port. A portion of the storage tank is controllably sealed to form a metering chamber in cooperation with the reduced diameter cup-shaped bottom. A first pump provides compressed air along a flow line to the metering chamber to force liquid from the metering chamber and through the chamber outlet port. A sensor senses pressure in the flow line and provides a sensed pressure signal indicative thereof. A controller commands the first pump on, monitors the sensed pressure signal and turns the first pump off after detecting that the sensed pressure signal value has dropped below a threshold value indicating the predetermined volume of liquid has been delivered through the chamber outlet port.
The system may also include a second air pump that delivers a second flow of compressed air downstream of the metering chamber outlet port and upstream of the cartridge inlet in response to a brew interrupt signal received by the controller to drive the liquid downstream of the metering chamber outlet port to the cartridge. Advantageously, this allows a user to control the strength of their brewed beverage by using less water than the nominal amount dispensed by the brewer when the brew interrupt bottom is not depressed during a brew cycle.
These and other objects, features and advantages of the present invention will become apparent in light of the following detailed description of preferred embodiments thereof, as illustrated in the accompanying drawings.